Reducing aluminium by hydrocarbons.



iatented September 8 1903 PATENT OFFICE.

ABVID REUTERDAHL, or PROVIDENCE, RHODE ISLAND.

RE DUCING ALUMINIUM B Y H YDROCARBONS.

SPECIFICATION forming part of Letters Patent N 0. 738,733, dated September 8, 1903.

Application filed October 16, 1902. Serial No. 127,585. (No specimens.)

To all whom it may concern:

of Reducing Alumina by Hydrocarbons, of

which the following is a specification.

This invention relates to the reduction of alumina (Al O lby means of hydrocarbons .and adequate heat. The alumina may be produced in any manner whatsoever from the ores containing aluminium, such as bauxite,'

cryolite,

corundum, kaolin, or from ordinary clay. The process does not pertain to the manner of obtaining alumina (A1 0 from the aluminium-bearing ores,but to the hereindescribed method of reducing alumina and setting free the aluminium.

In carrying out my process in the best manner I take alumina (A1 0 in finely-powdered form and thoroughly mix it with a suitable liquid hydrocarbon, adding, by preference, a generous amount of powdered coal or lampblack. This mixture I work into a paste with oil of turpentine (0 11 or benzin (C H as the preferred liquid hydrocarbon. The oil of turpentine when employed should not have been exposed to the air for any considerablelength of time before using, as it would thereby take up oxygen, which is clearly detrimental' to the success of the process. This paste is then let into the retort 1 (shown on the diagram) by means of the opening 2, the same being provided with the cover 3 and sliding bottom 4:. The gaseous hydrocarbon, such as acetylene, (0 11 is then let in through tube 5, a screen or perforated plate covering the inner end of the tube. If necessary, the acetylene may be forced into the retort underpressure. As is seen from the diagram, the acetylene is introduced at the bottom of the retort and must thus pass through and act upon the entire mass before escaping through the dome 6 and outlet-tube 7.

In the working of my process abundant heatis applied to the bottom of the retort] This heat is obtained from suitable forms of oxyhydrogen blow-pipes 8. The necessary number and power of such burners depends upon the area of the bottom of the j retort.

Oxygen and air can be used with very good results. If still higher heats are necessary,

county of Providence cavity oxygen and hydrogen will enable one to produce temperatures sufticiently highto completely reduce the entire contents of the retort.

The gaseous products of reduction pass ofi by means of tube 7 from the dome or arched To help draw the acetylene gas through the mass in the retort and also to quickly remove the gaseous products of reduction, a vacuum,

pump may be connected to tube 7 and may be put into operation as soon as the acetylene is turned on, thereby introducingthe gas into the retort by suction.

In order to complete the reduction of the mass, a temperature ranging between 1,900 centigrade and 2,000 centigrade willbe necessary. This temperature can be obtained by the means already described.

I use oil of turpentine or benzin in producing my paste,because both of these substances contain nothing but carbon and hydrogen. They also possess the valuable property of changing into nothing but other types of by drocarbons when heated. The powdered coal or lampblack is also valuable as an auxiliary in the process of reduction as it tends to take up any free oxygen which may not already have been taken care of by the dissociated hydrocarbons, thus tending to prevent free oxygen from reuniting with aluminium.

The success of the process depends upon the fact that each particle of'alumina has pre sented to it a substance or compound rich in carbon and hydrogen. My peculiar treatment is thus a gaseous and a liquid hydrocarbon fusion process.

When the entire mass has been reduced, the acetylene is turned cit. The vacuumpump may be continued in operation for a short time after the shutting off of the acetylene in order to be surethat all thegas' 'eous products of reduction have been carried away. The sliding bottom 4 of the retort 1 is then pulled out, the contents removed and subsequently melted, and the aluminium run into suitable molds.

The accompanying diagram illustrates the style of furnace which may be used in carrying out my process.

The retort should be made from such material as is used in the manufacture of high .a proper mixture of kaolin, clay, and lime and should be glazed on boththe inside and outside. This glazing should also be applied to both sides of the sliding bottom 4.

The tubes, whichare used as indicated in drawing, may be made of the same material which is used for the retort and should be glazed on both sides, or they may be made from compressed lime only.

All the tubes are removable in order that they may be inspected, cleaned, or replaced easily when necessary. The remainderot' the furnace is constructed from fire-brick 9. Fireclay and cement are used between contiguous surfaces, and all surfaces exposed to action of reduction products are highly'glazed.

I claim as my inventionthe powdered alumina a suitable liquid hydrocarbon so as to produce a paste-like compound, then subjecting the sa-me to adequate heat in a closed vessel or retort and simnltaneously passing through the mass a current of hydrocarbon gas, and finally removing the metallic alu minium,substantially as set forth.

2. The method herein described-of reducing powdered alumina and setting free the aluminium therein, consisting in mixing with the powdered alumina a suitable liquid hydrocarbon so as to produce a paste-like compound, then subjecting the same to adequate heat in a closed vessel or retort and simultaneously passing through the mass a current of acetylene, and finally removing the aluminium, substantially as set forth.

3. The reduction of alumina and setting free the aluminium. therein, by finely dividing the alumina and making it into a paste with some suitable liquid hydrocarbon together with some finely-divided and suitable form of carbon, and by passing through the entire mass a gaseous hydrocarbon, and simultaneously applying adequate heat thereto, substantially as set forth.

4:. Thereduction of powdered alumina and setting free the aluminium therein, by making it into a paste with oil of turpentine together with some finely-divided and suitable form of carbon and by passing through the entire mass a gaseous hydrocarbon, and applying adequate heat thereto, substantially l. The method herein described of reducitfg powdered alumina and setting free the aluminium therein, consisting in mixing with as set. forth.

5. The reduction of alumina and setting free the aluminium the-rein, by forming a paste-like compound of powdered alumina and carbon and liquid hydrocarbon, intimately intermixed; subjecting the mass to adequate heat in a s uitable retort, and simultaneouslypassing a current of gaseous hydrocarbon upwardly through the mass and exhausting the-gaseous current and products by suction, substantially as set forth.

In testimony whereof "I have affixed my 'signature in presence of two witnesses.

ARVID REUTERDAHL.

Witnesses: l

A. H. SPENCER, H. W. LADD. 

